哺乳动物受精过程的分子机制是困扰科学家多年并亟待解决的问题。精子表面蛋白Izumo1和刚发现的其在人卵子上的受体Juno的相互作用是精卵识别所必须的。它们是目前发现的第一个精卵细胞表面受体-配体蛋白对。目前绵羊Izumo1和Juno基因的功能研究尚未见报道。本项目围绕绵羊Izumo1和Juno基因与绵羊繁殖力的关系这一科学问题，以不同繁殖力的小尾寒羊为主要对象，采用生理学、遗传学和分子生物学方法，重点探究：（1）不同繁殖力小尾寒羊的生殖生理性状差异；（2）绵羊Izumo1和Juno基因序列多态性及其与繁殖力的关联；（3）两基因在小尾寒羊各组织和配子成熟各阶段中的表达规律；（4）通过双吸管粘附、体外受精和异种融合试验分析绵羊Izumo1和Juno基因之间的功能互作。本结果预期阐明Izumo1和Juno基因与绵羊繁殖力的关系，可为研究哺乳动物受精过程的分子机制提供重要线索。

Little is known about the molecular mechanisms that induce gamete fusion during mammalian fertilization. Izumo1 is an essential sperm cell-surface protein, its receptor Juno on the egg has been identified newly. As the first identified ligand-receptor pair on sperm and egg, the Izumo1-Juno interaction is a necessary event for adhesion between sperm and egg. No research about the gene function of Izumo1 and Juno in sheep was done. We propose to explore the association of these two genes and sheep fecundity by methods of physiology, genetics and molecular biology. This project focus on Small Tail Han sheep with different fecundity mainly, to address the questions as follows: (i) The difference of reproductive physiology of Small Tail Han sheep with different fecundity; (ii) Gene polymorphism of Izumo1 and Juno and association analysis with sheep fecundity; (iii) Expression of Izumo1 and Juno in different tissues and different stages of gamete maturation of Small Tail Han sheep; (iv) Describing the interaction of Izumo1 and Juno in fertilization through dual-pipette assays, in vitro fertilization assays and heterologous adhesion and fusion assays. We propose to elucidate the association of these two genes and sheep fecundity. These results will be a contribution to the research of molecular mechanisms during mammalian fertilization.